Combination flash and acoustic suppression system and method

ABSTRACT

A combination acoustic and flash suppression system and method for use with a weapon that fires a bullet. A noise suppressor module or section of the system is adapted to be connected to a distal end of a barrel of the weapon, and a flash suppressor module or section of the system is adapted to be connected to the outlet end of the noise suppressor module, so that the downstream position of the flash suppressor module relative to the noise suppressor module helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port so as to suppress both flash and noise.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. 13/764,380, filed Feb. 11, 2013, entitled “SYSTEM AND METHOD FOR MULTI-STAGE BYPASS, LOW OPERATING TEMPERATURE SUPPRESSOR FOR AUTOMATIC WEAPONS” which is incorporated herein by reference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the United States Department of Energy and Lawrence Livermore National Security, LLC for the operation of Lawrence Livermore National Laboratory.

FIELD OF THE INVENTION

The present disclosure relates to noise and flash suppressors, and more particularly to a combined noise and flash suppression system and method for suppressing both acoustic and flash signatures from the muzzle of a weapon by Mach disk disruption.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Firearms typically produce noise and flash. Flash is typically reduced by attaching a flash suppressor (aka “flash hider”) on the end of the muzzle, and many weapons are routinely used with such flash suppressors. For example, most military firearms (excluding pistols) are equipped with roughly cylindrical devices that attach to the end of the muzzle that have slots, holes or other form of vent openings to partially vent the escaping gases, and which provide flash reduction relative to a bare muzzle. However, the physics of flash generation and reduction has not been well understood, and the merits of variations in design between competing manufacturers is not clear. Furthermore, when it is desirable and/or required to also lessen the noise from a weapon, an acoustic or noise suppressor (aka “silencer”, and typically large substantially cylindrically-shaped can) is attached to the end of the weapon, usually attaching over the entirety of the existing flash suppressor if the weapon has a flash suppressor already attached.

Conventional noise suppressors typically perform acoustic suppression using internal baffles and chambers that both trap and delay the propellant gasses from exiting the barrel of the weapon. Such previous noise suppressor designs generally operate by expanding and cooling the hot expanding propellant gasses in the internal chambers of the suppressor, then delaying the release of the expanding propellant gasses, which transfers heat to the suppressor. The additional time that the propellant spends in the suppressor before being discharged to the ambient atmosphere results in a reduced acoustic signature. Other methods for suppressing/reducing noise may include, for example, using sinuous flow paths to delay the exit of propellant gases from the discharge port and reduce exit pressures, using sound insulating material in the sidewalls, etc. In any case, while such noise suppressors do operate to reduce noise levels, they do not silence the weapon completely. For example, noise reduction is at best ˜35 db, at a few meters from the muzzle, compared to an unsuppressed noise level that can be as high as ˜180 db. Moreover, attaching a noise suppressor completely over the flash suppressor can defeat the functioning of the flash suppressor so that flash re-appears at the discharge port of the noise suppressor.

SUMMARY

One aspect of the present invention includes a combination acoustic and flash suppression system for use with a weapon that fires a bullet, the system comprising: a noise suppressor module having a body portion with an inlet end adapted to be connected to a distal end of a barrel of the weapon, an outlet end, and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the noise suppressor module is connected to the distal end of the barrel; and a flash suppressor module having a body portion with an inlet end adapted to be connected to the outlet end of the noise suppressor module, an outlet end with a discharge port, a bore in communication with the discharge port extending between the inlet and outlet ends of the flash suppressor module concentric with the bore axis of the barrel when connected to the outlet end of the noise suppressor module, and sidewall openings communicating with the bore, whereby the downstream position of the flash suppressor module relative to the noise suppressor module helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port.

Another aspect of the present invention includes a noise and flash suppressor for use with a weapon that fires a bullet, the suppressor comprising a body having: a noise suppressor section including an inlet end adapted to be connected to a distal end of a barrel of the weapon; a flash suppressor section including sidewall openings and an outlet end with a discharge port, and located downstream of the noise suppressor section when the inlet end is connected to the distal end of the barrel; and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the inlet end is connected to the distal end of the barrel, and in communication with the discharge port and the sidewall openings of the flash suppressor section, whereby the downstream position of the flash suppressor section relative to the noise suppressor section helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port.

Another aspect of the present invention includes a method of suppressing noise and flash from a weapon that fires a bullet, the flash and noise being generated by expanding propellant gasses exiting from a distal end of a barrel of the weapon as the bullet is fired from the weapon, the method comprising: providing a noise suppressor module having a body portion with an inlet end adapted to be connected to a distal end of a barrel of the weapon, an outlet end, and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the noise suppressor module is connected to the distal end of the barrel; providing a flash suppressor module having a body portion with an inlet end adapted to be connected to the outlet end of the noise suppressor module, an outlet end with a discharge port, a bore in communication with the discharge port extending between the inlet and outlet ends of the flash suppressor module concentric with the bore axis of the barrel when connected to the outlet end of the noise suppressor module, and sidewall openings communicating with the bore; securing the inlet end of the noise suppressor module to the distal end of the barrel; and securing the inlet end of flash suppressor module to the outlet end of the noise suppressor, whereby the downstream position of the flash suppressor module relative to the noise suppressor module helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port.

Generally, the present invention involves a combination noise and flash suppression system configured to provide both acoustic and flash suppression by relatively positioning a flash suppressor module or section of the system downstream of a noise suppressor module or section of the system so as to be adjacent a discharge port where a bullet (or other projectile) exits the weapon. In one example embodiment, a noise suppressor module or component of the system is adapted to be attachable to a muzzle (i.e. a distal end of a barrel) of a weapon, and a separate flash suppressor module or component of the system is adapted to be attachable to an exit end of the noise suppressor component. In an alternative embodiment, a noise suppressor section and an adjacent flash suppression section may be integrated together and provided as part of a single-bodied suppressor unit, with the unit suppressor being connectable to the muzzle so that the flash suppression section is positioned downstream of the noise suppression section.

The advantage of positioning the flash suppressor module or section downstream of the noise suppressor module or section and adjacent the discharge port is that the vent ports of the flash hider can operate to cause disruption of the shock front, also known as “Mach disk,” that forms when the supersonic flow of the expanding propellant gases exits the muzzle at supersonic velocities, and which is often observed when shooting a bare muzzle weapon (i.e., with no suppressor or flash hider attached). It is appreciated that the “Mach disk” defines the location where the supersonic flow slows abruptly due to its interaction with the surrounding pressure field, and can be characterized as a “shock” normal to the flow direction (which tends to form at about 10-15 bore diameters from the bare muzzle, or at about 9 cm for a 7.62 mm caliber weapon). Such an abrupt decrease in flow velocity at the Mach disk creates a large compression and a very large increase in temperature of the hot propellant gases, such that the gases are hot enough to emit light and cause a “flash.” Thus, by positioning the flash suppressor module or section downstream of the noise suppressor module or section to disrupt the Mach disk, there cannot be a large temperature rise in the downstream flow, and both noise and flash can be mitigated. Disruption of the Mach disk may be caused by the weakening of the flow due to gas venting through the ports of the flash hider or by physical disruption of the Mach disk due to the end of the flash hider being located in the region where the Mach disk would otherwise form.

FIGS. 2-4 show a progressive time sequence at approximately 0.25 ms intervals of a comparative computer simulation of a 25 mm bullet 71 shot from both a bare muzzle 70 without a flash hider, and a muzzle 70′ with a flash hider 80 (scaled from a 50 caliber Vortex M2E2 flash eliminator) attached to it. Only hot air with temperature in excess of 800K is shown. Beginning at FIG. 2, hot propellant (not shown) is contained behind the bullet 71 which is shown positioned still within the muzzle. As shown by hot air 81, 82, and 83 in FIGS. 2-4, at progressively further downstream positions from the bare muzzle 70, there is an increase in temperature observed (due to creation of Mach disk) when a flash hider is not utilized. In contrast, the muzzle 70′ with flash hider 80 shows hot air only at the flash hider but not otherwise observed at downstream positions from the flash hider. This simulation shows that the flash suppressor disrupts the Mach disk, so that there is no hot air present to initiate combustion of the propellant gases.

FIGS. 5A and 5B show normal and enlarged views, respectively, of two simulations of a bullet shot from a bare muzzle (shown at bottom half of figures) and a muzzle with a flash hider (shown at top half of figures). Disruption of the Mach disk can be readily seen in the enlarged view of FIG. 5B, with a substantial temperature difference. It is notable that inaccurate heat capacities (which have no effect on the simulation, only on the temperature scale of the visualization) underpredict the actual temperatures. FIG. 6 shows the same image as FIG. 5 but ˜1.5 ms later in time. There is no Mach disk present (hence no temperature rise) in the top half of the figure associated with the muzzle with flash hider, but a pronounced one in the bottom half of the figure associated with the bare muzzle.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way

FIG. 1 is a longitudinal cross-sectional view of an example embodiment of the combination flash and acoustic suppression system of the present invention.

FIGS. 2-4 show a progressive time sequence in approximately 0.25 ms intervals, of two simulations of a bullet shot from a bare muzzle and a muzzle with a flash hider.

FIGS. 5A and 5B show normal and enlarged cross-sectional views, respectively, of two simulations of a bullet shot from a bare muzzle (shown at bottom half of figures) and a muzzle with a flash hider (shown at top half of figures).

FIG. 6 is a cross sectional view of the two simulations following FIGS. 5A and 5B at ˜1.5 ms later in time.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

Turning now to the drawings, FIG. 1 shows a combination flash and acoustic suppression system in accordance with one embodiment of the present disclosure, generally indicated at 40, and attached to a distal end 11 of a barrel 10 of a weapon. The weapon may be various types of firearms having a barrel for shooting a projectile (e.g. bullet) therefrom, such as for example, handguns, machine guns, semi-automatic weapons, etc. And the system 40 may be made from any material that is suitable for withstanding the high temperatures that are encountered from firing ammunition from a weapon. In one embodiment the suppressor is made from steel, but other materials, for example, titanium, Inconel or any other suitable high strength material could be used as well.

The system 40 is shown having two modules or components, namely a noise suppressor module indicated at 50, and a flash suppressor module indicated at 60. Dashed line 12 represents an axial center of the bore of the barrel 10 (i.e., the “bore axis”) as well as the axial center of a bore 53 of the noise suppressor module 50 and the bore 63 of the flash suppressor module 60. As drawn in FIG. 1, during firing of a cartridge from the weapon, a bullet from the cartridge will travel from left to right, first through the noise suppressor module, component, or section 50, then through the flash suppressor module, component, or section 60. The two modules are shown as two separate units which may be connected together into the system 40 of the present invention. It is appreciated that the two units may in the alternative be integrally formed as a single unit so long as the noise suppressor section of the unit system is adapted to be connected to the barrel with the flash suppressor section positioned downstream of the noise suppressor section.

The noise suppressor component 50 has a body with an inlet end 51, an opposite outlet end 52, and a bore 53 extending between the inlet and outlet ends concentric with a bore axis 12 of the barrel 10 when the noise suppressor module 50 is connected to the distal end 11 of the barrel. In this regard, the inlet end 51 is adapted to be connected to a distal end of a barrel of the weapon, such as by a conventional threaded connection or by any other suitable method or means of attachment, such as for example a quick connect/disconnect mechanism. In particular, FIG. 1 shows the bore 53 at the inlet end 51 having internal threads adapted to receive external threads on the distal end 11 of the barrel 10, as is well known in the firearms industry. Furthermore, the noise suppressor module may be particularly constructed with an internal construction designed to attenuate noise, such as for example, using baffles such as shown at 54 projecting orthogonal relative to the dashed line 12. The baffles 54 may be spaced apart from one another along a portion of the length of the noise suppressor portion 50, but do not necessarily need to have the same radial extent (i.e., dimension) as depicted in FIG. 1. The baffles 54 impede the flow of the expanding propellant gases out from the noise suppressor module 50 and slow the buildup of pressure therein and through the flash suppressor module 60, to reduce the peak pressure, pressure gradients, and temperature of the expanding propellant gasses when they initially exit the barrel 10. Other alternatives for effecting noise reduction may include, for example, using sinuous flow paths to delay the exit of propellant gases from the discharge port and reduce exit pressures as described in U.S. patent application Ser. No. 13/764,380, filed Feb. 11, 2013, entitled “SYSTEM AND METHOD FOR MULTI-STAGE BYPASS, LOW OPERATING TEMPERATURE SUPPRESSOR FOR AUTOMATIC WEAPONS” for disrupting the Mach Disk, using sound insulating material in the sidewalls, etc.

The flash suppressor module 60 is shown having a body with an inlet end 61 adapted to be connected to the outlet end 52 of the noise suppressor portion, an outlet end 62 with a discharge port 65, and a bore 63 in communication with the discharge port 65 and extending between the inlet and outlet ends 61, 62 of the flash suppressor module concentric with the bore axis 12 of the barrel 10 when connected to the outlet end 52 of the noise suppressor module 50. The flash suppressor module 60 is also shown having slots 64 (of a four prong flash hider device) communicating with the bore 63, and providing additional exit points for the propellant gases to exit the flash suppressor prior to the discharge port 65, which helps to reduce the quantity, pressure, and temperature of the propellant gases exiting from the discharge port, to thereby reduce the likelihood of flash production. It is appreciated that other forms, shapes, sizes of sidewall openings may be used in the alternative, such as for example vent holes, ports, etc. In this manner, the downstream position of the flash suppressor module 60 relative to the noise suppressor module 50 helps to disrupt a Mach disk from forming at a downstream location from the discharge port 65 when a bullet fired from the barrel 10 exits from the discharge port, as described in the Summary.

While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art. 

We claim:
 1. A combination acoustic and flash suppression system for use with a weapon that fires a bullet, the system comprising: a noise suppressor module having a body portion with an inlet end adapted to be connected to a distal end of a barrel of the weapon, an outlet end, and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the noise suppressor module is connected to the distal end of the barrel; and a flash suppressor module having a body portion with an inlet end adapted to be connected to the outlet end of the noise suppressor module, an outlet end with a discharge port, a bore in communication with the discharge port extending between the inlet and outlet ends of the flash suppressor module concentric with the bore axis of the barrel when connected to the outlet end of the noise suppressor module, and sidewall openings communicating with the bore, whereby the downstream position of the flash suppressor module relative to the noise suppressor module helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port.
 2. A noise and flash suppressor for use with a weapon that fires a bullet, the suppressor comprising a body having: a noise suppressor section including an inlet end adapted to be connected to a distal end of a barrel of the weapon; a flash suppressor section including sidewall openings and an outlet end with a discharge port, and located downstream of the noise suppressor section when the inlet end is connected to the distal end of the barrel; and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the inlet end is connected to the distal end of the barrel, and in communication with the discharge port and the sidewall openings of the flash suppressor section, whereby the downstream position of the flash suppressor section relative to the noise suppressor section helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port.
 3. A method of suppressing noise and flash from a weapon that fires a bullet, the flash and noise being generated by expanding propellant gasses exiting from a distal end of a barrel of the weapon as the bullet is fired from the weapon, the method comprising: providing a noise suppressor module having a body portion with an inlet end adapted to be connected to a distal end of a barrel of the weapon, an outlet end, and a bore extending between the inlet and outlet ends concentric with a bore axis of the barrel when the noise suppressor module is connected to the distal end of the barrel; providing a flash suppressor module having a body portion with an inlet end adapted to be connected to the outlet end of the noise suppressor module, an outlet end with a discharge port, a bore in communication with the discharge port extending between the inlet and outlet ends of the flash suppressor module concentric with the bore axis of the barrel when connected to the outlet end of the noise suppressor module, and sidewall openings communicating with the bore; securing the inlet end of the noise suppressor module to the distal end of the barrel; and securing the inlet end of flash suppressor module to the outlet end of the noise suppressor, whereby the downstream position of the flash suppressor module relative to the noise suppressor module helps to disrupt a Mach disk from forming at a downstream location from the discharge port when a bullet fired from the barrel exits from the discharge port. 